ARCATA, Calif.— The Center for Biological Diversity today filed a formal notice of intent to sue the U.S. Fish and Wildlife Service for failing to make a listing decision on a petition to protect the Humboldt marten, one of the world’s most endangered mammals. “Fewer than 100 Humboldt martens are thought to survive,” said Tierra Curry, a biologist with the Center. “This critically rare animal needs the full protection of the Endangered Species Act, right now, while there’s still time to save it.”

In 2010, the Center and allies petitioned for protection for the marten under the Endangered Species Act. The Service determined in January that the marten “may warrant” protection as an endangered species, but has failed to make a required 12-month finding to determine whether protection is warranted.

A cat-sized carnivore related to minks and otters, the Humboldt marten was once relatively common but is now found only in coastal old-growth forests in Northern California and southern and central coastal Oregon.

Because almost all of its old-growth forest habitat has been destroyed by logging, the Humboldt marten was believed extinct for 50 years. It was rediscovered on the Six Rivers National Forest in 1996, and in 2009, the first marten to be photographed in recent times was detected in Prairie Creek Redwoods State Park by remote-sensing camera. The historic range of the marten extends from Sonoma County in coastal California north through the coastal mountains of Oregon. In Oregon, the marten lives in the Siskiyou and Siuslaw national forests.

These extremely secretive animals are known for their slinky walking motion and ability to prey on porcupines by biting them on the face. Typically about two feet long, with large, triangular ears and a long tail, they eat small mammals, berries and birds, and are preyed on by larger mammals and raptors.

“There’s no question that the Humboldt marten needs and deserves Endangered Species Act protection,” said Curry. “We hope the Service will issue a proposed listing without us having to actually file a lawsuit.”

The Center for Biological Diversity is a national, nonprofit conservation organization with more than 350,000 members and online activists dedicated to the protection of endangered species and wild places.